Classic/Antique Car Repair: Plymouth 218 valve timing, timing gears, cam shaft

Question
I am working on a 1951 Plymouth 218 flat head 6.  My problem is when the timing marks on the timing gears are lined up the number one piston is not at tdc.  The piston reaches tdc when the crankshaft gear is aprox 40 degrees off the timing mark.

I compared the new gears to the old ones and the timing marks are in the same place in relation to the keyway.

Since the gears are keyed on to the crank and cam shaft I don't see how I could have put it together wrong.

Any ideas?

Answer
I found a note in one of my reference manuals relating to this engine and timing chain replace ment. It says, "it is immaterial which cylinder is at top dead center when the timing chain is replaced with the marks on the crank gear and cam gear opposite each other."
Brad